Nitrate Poisoning in Livestock, Horses, learn how to tell and how to prevent it.

Nitrate Poisoning

Nitrate poisoning occurs in humans, cattle, goats, horses, dogs, birds, sheep and swine to a lesser degree. What you should know about what your pastured animals eat everyday!Things you should know about the grasses and plants in your pasture. Don't Miss our NEW page about Tansy Ragwort control!

Hunter's Pony Farm offers this information as a service to our readers, we are not veterinarians, and take no responsibility for errors or consequences of using this information. If you are concerned about your animal, you should consult a licensed veterinarian immediately.

Have you ever wanted to know the poisonous or toxic
plants that could be growing in your pasture? With the news of foals dying from the possible injestion of cherry leaves it is fresh in our minds now to consider what our own horses may be exposed to in the pasture. Use the lists below to learn more about the plants that may be growing in your grass!

What about the things you hear about bugs in hay?

Well, this is the place to find out about those problems...
ones faced not just by horse owners, but farmers,
cattle and dairy farms, goat keepers, hay growers and others. Some of these plants are even poisonous to you and me! So read on, then check your pasture!

There are a few topics I want to cover here:
    *    Nitrate Poisoning
    *    Sudan Grass (sorghum)
    *    Blister Beetles
    *    Tall Fescue Toxicity
    *    Johnson Grass

The nitrate ion itself is relatively non toxic, it is when the nitrate is broken down in the digestive system that the trouble occurs.

Nitrate becomes nitrite which becomes ammonia, which becomes a protein. It is the nitrite phase in the stomach(s) where some of the nitrite can enter the bloodstream where it changes into a chemical that reduces the bloods ability to carry oxygen.

Oxygen starvation of the tissues occurs, along with a different process in which Prussic acid causes death of the tissues.

Nitrate poisoning happens when animals eat grass, hay, or drink water that contain large amounts of the chemical. This can come from plants, or from fertilizers used for farming.

Nitrates occur in most plants and in water, but sometimes the levels get so high as to become toxic. Grazing animals are usually poisoned by forage and hay. Nitrate consumption of as little as 0.05% of the animal's body weight may be lethal. Problems occur most often during cool temperatures, cloudy days or drought; also where heavy use of nitrate fertilizers occur. Nitrate formation increases when soil temperatures are 80 - 90 degrees. Low light (cloudy days) and night time causes nitrates to build up in plants, it is dispersed when sunlight hits the plants. The accumulation of nitrates in plants is a natural process. The plant gathers nitrogen through its root system and then stores it as nitrate in the stems. This nitrogen is later converted to protein in the leaves.

Horses can tolerate up to 0.50% nitrate in their total dry matter diet. A rule of thumb is to select hay for horses that contains no more than 0.65% nitrate ion on a dry matter basis.

Poisoning happens quickly, animals may be found dead before symptoms are noticed. Here is what to look for:

    *    Animal stays out of herd
    *    may collapse, fall in their tracks
    *    weakness
    *    unsteady gait
    *    shallow and rapid breathing
    *    rapid pulse
    *    diarrhea
    *    frequent urination
    *    frothing at the mouth
    *    coma
    *    death accompanied by muscular reflex movements
    *    white of eye, tongue, lips may have a blue-brown
          discoloration
    *    blood is chocolate brown in color
    *    pregnant animals may abort

Other issues include animals ingesting plants that are "borderline"
in toxicity causing abortion, reduced milk flow, lower weight gains,
vitamin A deficiency.

Plants to watch out for:
Field Crops
    * alfalfa
    * millet
    * soy bean
    * barley
    * oats
    * soy bean
    * corn
    * rape
    * sudan
    * fescue
    * rye
    * wheat

Vegetables
    * beets
    * lettuce
    * spinach
    * celery
    * mangles
    * squash
    * cucumbers
    * parsnips
    * swiss chard
    * kale
    * radishes
    * turnips

Weeds
    * bindweed
    * elderberry
    * Russian thistle
    * blue-green algae
    * fiddleneck
    * smartweed
    * bull thistle
    * goldenrod
    * stinging nettle
    * burdock
    * lambsquarter
    * sunflower
    * Canadian thistle
    * nightshades
    * velvetweed
    * carelessweed
    * ragweed
    * whitecockle

Other plants may have toxic levels under certain conditions.

Management Practice
* Feeding rations high in carbohydrates will reduce and some times prevent losses from nitrate poisoning* Control weeds that accumulate nitrates. Freshly sprayed plants may become more palatable, so defer grazing of sprayed areas.
* During periods of cool or cloudy weather. avoid grazing a suspect area if possible. During periods of sunlight allow’ animals to eat large quantities of dry forage and then graze the area.
* Test the nitrate content of forage when in doubt.
* Distinguish nitrate poisoning from prussic acid poisoning or grass tetany, so the appropriate treatment may be administered.
* OAT HAY MOISTENED WITH WATER can convert nitrates to nitrites in a short time.

Guide B-807, Christopher D. Allison, Extension Range Management Specialist
College of Agriculture and Home Economics, New Mexico State University
http://www.cahe.nmsu.edu/pubs/_b/b-807.html